Numbness of the scalp is sometimes an effect of emotional factors and sometimes a precursor to disease. For example, when watching a horror movie, many people will have numbness in the scalp, and sometimes in case of stress, there will be such discomfort. These are related to emotional factors and are normal reactions of the body, not diseases. If the hair is inexplicably numb, sometimes it is cervical spondylosis compression caused by insufficient blood supply to the scalp of the brain. If you have hypertension and your scalp goes numb, you can’t rule out that it’s a sign of a stroke precursor.